In a 48-page memo, prosecutors told U.S. District Judge Ellen Huvelle that Griles assisted lobbyist Jack Abramoff in return for jobs and other favors for four female "close personal friends," The Washington Post reported.

Griles, who is scheduled to be sentenced later this month, pleaded guilty in March to obstructing an investigation by the Senate Indian Affairs Committee, in a deal that bars prosecutors from seeking a sentence of more than 10 months with half to be served in a halfway house. Griles' lawyers have asked for a sentence of probation and community service.

In the memo, prosecutors said Griles, by lying to the Senate panel, prevented it from uncovering the "the secret, unique, sustained and unfettered access" he gave Abramoff.

Italia Federici, one of Griles' former girlfriends, has also pleaded guilty, agreeing to cooperate with the investigation.

Griles did not cooperate with investigators, the newspaper said.

Abramoff made large donations to the group Federici headed, the Council of Republicans for Environmental Advocacy.